Process for treating a filamentary strand



Jan. 14, 1969 A. L. BREEN ET AL PROCESS FOR TREATING A FILAMENTARYSTRAND Sheet of 4 Filed Oct. 24, 1967 INVENTORS ALVIN L. BREEN HERBERT-G. LAUTERBACH fi 5 T ATTORNEY Jan. 14, 1969 A, L. BREE-N ET AL 3,421,194

PROCESS FOR TREATING A FILAMENTARY STRAND Filed Oct. 24, 1967 Sheet 3014 &

INVENTORS ALVIN L. BREEN HERBERT G. LAUTERBACH BY WiMm ATTORNEY Jan. 14,1969 A. L. BREEN ET AL PROCESS FOR TREATING A FILAMENTARY STRAND SheetFiled Oct. 24, 1967 FIG. 5

FIG. 4

pun I INVENTORS ALVIN L. BREE N HERBERT G. LAUTERBACH MW ATTORNEY Jan.14, 1969 v y BREEN ET AL 3,421,194

PROCESS FOR TREATING A FILAMENTARY STRAND REVERSAL POiNT Filed 001.. 24,1967 Sheet 4 of 4 no. DIRECTION 0? OF 12/ TURINS 'TWIST E,

REVERSAL POlNT 3 i L07; a z I a: w 0m 1 :2 2 REVERSAL E POINT E a I o a2 s 4 5 e 1 2 s MC TENACITY, GPD

\k 5 FIG. l3 REVERSAL POINT l 74 4 V v 2 l i w z k 2 FILAIENT BREAKEwncmoM INVENTORS ALVIN L. BREEN HERBERT G. LAUTERBACH V ATTORNEY UnitedStates Patent 3,421,194 PROCESS FOR TREATING A FILAMENTARY STRAND AlvinL. Breen and Herbert G. Lauterbach, Wilmington,

Del., assignors to E. I. du Pont de Nemours and Company, Wilmington,Del., a corporation of Delaware Continuation-impart of applications Ser.No. 698,103, Nov. 22, 1957, and Ser. No. 70,269, Nov. 18, 1960.

This application Oct. 24, 1967, Ser. No. 684,583 US. Cl. 2872 4 ClaimsInt. Cl. D02g 3/02; D02j 1/00 ABSTRACT OF THE DISCLOSURE References torelated applications This is a continuation-in-part of copendingapplication Ser. No. 698,103 filed Nov. 22, 1957, and now abandoned, andof copending application Ser. No. 70,269 filed Nov. 18, 1960, as acontinuation-in-part of application Ser. No. 842,524, filed Sept. 25,1959, and both now abandoned.

This invention relates to a fluid treatment process for treating afilamentary strand such as yarn or thread to provide improveddyeability.

Artificial fibers are normally produced most easily as continuousfilaments. These continuous filament yarns are very strong because ofthe absence of loose ends that are unable to transmit imposed stresses.Their extreme uniformity and lack of discontinuity, however, makesconventional continuous synthetic filament yarns much more dense thanyarns made from synthetic staple fibers. The production of yarn fromstaple fibers, however, is time-consuming and requires a complex seriesof operations to crimp the fibers, align the fibers into an elongatedbundle and then to draw the bundle to successively smaller diameters.The final spinning operation, which involves a high degree of twist,finally binds these discontinuous fibers together to produce a coherentyarn with consido erably increased bulk. The occulded air spaces givethem a lightness, covering power, and warmth-giving bulk not normallypossible with continuous filament yarns. Thus to get staple fibers thatcan be processed on conventional wool or cotton spinning equipment, ithas been the practice to cut continuous filament yarns such as rayon,acetate, nylon, as well as the polyacrylic and polyester fibers intoshort lengths for spinning into staple yarn.

Recent developments in the textile industry have provided useful routesfor improving the bulk and covering power and recoverable elongation ofcontinuous filament yarns without resorting to the staple spinningsystems of the prior art. A well-known process for making stretch yarninvolves the steps of twisting, heat-setting and then backtwisting to alow final twist level. Another yarn of improved bulk is preparedcommercially by the steps of twisting, heat-setting and backtwistingon-the-run using a false-twisting apparatus. This end product can befurther modified by hot relaxing to improve the bulk and handle. Stillanother bulk yarn is being prepared by the wellknown stuffer boxtechnique wherein the yarn is steamed ice to heat-set while it is in acompressed state in the stutter box.

All of these yarns of the prior art are produced by a process which hasthe common elements of deforming the yarn mechanically and thenheat-setting either with or without an after-relaxation step. It was notuntil the recently disclosed product in US. Patent No. 2,783,609 issuedMar. 5, 1967, to Breen and its process of manufacture became known thatan entirely new technique became available for improving the bulk ofcontinuous filament yarns. This techniques involves exposing afilamentary material to a rapidly moving turbulent fluid, therebyinducing a multitude of crunodal filament loops at random intervalsalong the individual filaments. These loops and snarls of entangledloops increase the bulk of the continuous filament yarns considerablyand result in fabrics of improved cover, bulk, handle, and the like.With the invention of Breen, a new tool is available for the bulking offilamentary structures, i.e., a turbulent fluid. Fluids, of course, havebeen used for yarn treating in many of the prior art operations such asdrying, extracting, transporting, and the like. Until the invention ofBreen, however, they had not been used to entangle, convolute, and bulka filamentary material. It has now been discovered, however, that a newprocess utilizing the turbulent fluid technique results in new yarnproducts that have certain unique properties not heretofore disclosed inthe art.

It is an object of the present invention to provide a process fortreating a filamentary strand with fluid to provide improved properties,particularly with respect to dyeability. A further object is to providesuch a proess for producing yarn with a combination of desirabletenacity and a high rate of dyeability. Other objects will becomeapparent from the disclosure.

According to this invention, there is provided a process for treatingsynthetic organic filamentary strands to provide products having acombination of desirable tenacity and a high rate of dyeability whichhas not been attained heretofore. These products are produced by feedinga synthetic organic filamentary strand at an overfeed of at least about12% to a plasticizing stream of a compressible fluid in which theindividual filaments, while in a plastic state, are momentarilyseparated from each other and then cooled. The stream of compressiblefluid should be at a temperature above 275 F., preferably at least about300 F., and temperatures of 400-600 F. are usually desirable. The strandmay be cooled by passing through air at normal room temperature. Theprocess makes possible a product which has high tenacity and alsopossesses a rate of dyeability at least about greater than that of thefeed strand. By increasing the overfeed to at least 30%, preferably atleast 40%, the filamentary product produced contains, in addition to thehigh tenacity and high rate of dyeability set forth above, fiberspossessing an independent random, persistent, three-dimensional,non-helical, curvilinear configuration along the line of the filamentarystrand and is substantially free of stable crunodal loops.

The invention and the manner of carrying it out will be more clearlyunderstood by reference to the drawings in which,

FIGURE 1 is a schematic perspective view of apparatus suitable for theproduction of the improved yarn of this invention,

FIGURE 2 shows an alternate type of jet device for use in the apparatusof FIGURE 1,

FIGURE 3 is a schematic perspective view of equipment adapted tospinning, drawing and treating in successive steps without intermediatehandling or packaging,

FIGURES 4, 5, 6, 7, 8, 9 and 10 show various jet devices useful in theproduction of the yarn of this invention,

FIGURE 11 shows a single filament produced in accordance with thisinvention from a fiber of non-round cross section,

FIGURE 12 shows a graphical relationship between the dye absorption andorientation angle of the product of this invention, and its tenacity,based on the data of Example I,

FIGURE '13 shows a graphical relationship of the pilling index of theproduct of this invention, and its break elongation, and

FIGURE 14 is a schematic representation of the structuralcharacteristics of the filaments produced by this invention.

In FIGURE 1, the moving threadline 31 to be treated is passed throughguide 32, between feed rolls 33 and 34, over guide 35, through fluid jet36, over guide 37, through quench tube 38, provided with cooling fluidthrough opening 39, through guide 40, to guide 43, or alternatelybetween feed rolls 41 and 42. Traverse guide 44 may be used todistribute the treated yarn on package 46 driven by roll 45 or package46 may be a roll which with roll 45 is used to feed yarn to piddle tube47 provided with aspirating tube 48 depositing yarn in container 49.

In FIGURE 3, filaments 70 from spinneret 71 quenched asymmetrically bycold fluid directed to the face of the spinneret by fluid nozzle 72 areconverged at guide 73 and passed around rolls 74. The yarn iscontinuously drawn on draw pin 75 by wraps around rolls 76 moving athigher speed and is then fed through guides 78 and 79 and jet 80. Theyarn leaving the jet is passed around guide 81 and rolls 82. Quenchingdevice 84 cools the yarn or alternatively it is cooled by the flow ofcold air through box 87 around cooling rolls 82, 85 and 86. From thecooling rolls, the yarn is fed continuously through traverse guide 88 topackage 89 driven by roll 90.

FIGURE 6 is a jet suitable for the practice of this invention,consisting of body member 95, orifice member 96, held in place by clamp97 and screw 98. This jet is illustrated more fully in Hall US. PatentNo. 2,958,- 112 dated Nov. 1, 1960. The passage through orifice member96 consists of cylindrical opening 100, connecting with concentriccylindrical opening 101, and outwardly tapered opening 99, characterizedby the angle a. Yarn tube member 102, supporting hollow needle 103, inhole 104, with cutaway section giving a lip 105, is supported in bodymember 95, in an adjustable fashion by screw tightened in tapped hole106. The compressible fluid is applied to the nozzle at 107 and the yarnis fed to needle member through hole 108.

FIGURE 7 is another jet consisting of body member 110, and yarn guidemember 111, with perforated disc 112, and fluid entrance 113. Yarn isfed to this nozzle through opening 114.

FIGURE 2 is a similar jet particularly adaptable to multiple endoperation where precise temperature control is desired from position toposition. It consists of jet body 121, with opening 122 for theturbulent fluid, and replaceable orifice 123. Yarn guide member 124,provided with yarn opening 125, is machined so that tip 128 is eccentricto the jet axis. Jet body 121 is sealed in manifold 129 by gaskets 126and flanges 127.

FIGURE 10 is a simplified jet suitable for the practice of thisinvention consisting of body member 130 with drilled holes as shown toprovide a T-shaped intersection at 131. Thin-walled tubing 132connecting to compressible fluid supply through adapter 133 serves as acombination conduit and heater for the compressible fluid. Similarthin-walled tubing 134 attached to body member 130 serving as a yarnpreheater is provided .With yarn entrance 135. A high amperageelectrical current applied between lugs 136 and 137 beats thecompressible fluid passing through tube 132 by virtue of the electricalresistance of the tubing. Similarly, highamperage current appliedbetween lugs 138 and 139 provides additional heating to the turbulentfluid exhausting in a counter-current direction to the thread linemoving from toward 131. This arrangement preheats the yarn so that it isin a desirably plasticized state as it traverses the zone of greatestturbulence between 131 and 141. Turbulent fluid exhaustingpreferentially from orifice 141 produces the desired treating action.Insulation prevents excessive heat loss from tubes 132 and 134 and alsotends to support these fragile elements. This unit .is particularlyuseful for treating yarns at very high speeds in the range of 500 1000y.p.m. or more.

FIGURE 8 shows the intersection 131 of the jet in cross section ofFIGURE 10. It is to be understood that other devices employing heatedplates or rolls may be substituted for the preheater of FIGURE 10.Similarly, the preheating fluid could be a hot gas applied by anauxiliary nozzle or a hot liquid applied in an open bath orsemi-confining tube. Such devices likewise may be made as an integralpart of any of the fluid nozzles of FIGURES 2, 6, 7 or 9, or thosedescribed, for example, in Hall US. Patent No. 2,958,112 dated Nov. 1,1960, and U.S. Patent No. 2,783,609 to Breen, issued Mar. 5, 1957.

FIGURE 9 shows one form of jet particularly useful for the practice ofthe process of this invention as indicated in FIGURE 3 where the threadline being treated is taken directly from a spinning operation. In thiscase, body member is split into two similar portions. Likewise, yarnguide member 143 is split into similar parts, laying open the yarnpassage 144 and orifice 145. For stringup, these parts are held in theopen position by hinge 146. During the treating operation, the parts areheld in a closed position by hook 147 and pin 148. Screws 149 are usedto adjust the depth of yarn guide member 143 within body piece 150. Anadjustment of the opposing yarn guide members 143 to slightly differingdepths produces a desirable eccentricity of the turbulent fluid flowpattern. Other forms of jets similar in principle to FIGURE 9 but havingrotating or sliding parts or other mechanisms to provide access to theturbulent fluid chamber are likewise useful in the process of thisinvention.

For certain uses where enhanced luster and tactile dryness are desiredthe preferred product of this invention should be made from fibershaving a non-round shape of critically selected character. In carpetyarns, for example, it has been found preferable to use non-round fibersof the type disclosed in US. Patent No. 2,939,202 issued June 7, 1960,to Holland.

An important property of products of this invention which isparticularly noticeable with non-round fiber forms is illustrated inFIGURE 11. Here the fiber has not only a random, three-dimensional,non-helical, curvilinear configuration, but is also formed into arandomly twisted configuration, portions of which are in an S directionwith other portions being in a Z direction. The twist is completelyrandom along the length of the filament particularly with respect to 1)the angle of twist which varies continuously and randomly, (2) thenumber of twist reversals per inch of filament, and (3) the number ofturns between twist reversals. Each filament contains at least 2(absolute) turns per inch of twist (only full turns being counted).

It is very simple to observe filament twist in non-round filaments usingconventional optical techniques. Filament twist in round fiber forms isalso easily observed with an American Optical Baker InterferenceMicroscope using techniques specified by the manufacturer in theoperating manual for this microscope. To determine the extent of therandom twist modification of the individual fiber, a specimen is mountedbetween microscope slides with sufficient tension to hold the fiber axisin an approximately straight condition (but a tension low enough thatthe twist is not appreciably reduced). The angle is then measuredbetween imaginary lines following the outermost points of the filamentsand the filament axis at a number of points sufficient to provide ameaningful average. This average angle should be at least 1. There willbe points where the angle is essentially zero where the twist reversesdirection. Other points are found where the angle is considerablygreater than the average value. In well-modified samples maximum valuesin the order of 30 are observed and the average may be as much as 5 ormore.

FIGURE 14 depicts a straightened filament c of this invention having anon-round cross section with e representing a single element on thesurface of the filament (a line on the surface of the filament which, inthe straight filament, prior to twisting or crimping of the filament, isstraight and parallel to the axis of the filament). It will be notedthat the direction of twist is alternately S and Z in adjacent sectionsof the filament. The angle of twist of the filament at any point h ofelement e is shown by alpha, the acute angle between a tangent t toelement e at that point and plane i perpendicular to the plane of thepaper) which contains both the axis of the filament and point h. Infilaments of this invention, both crimped and uncrimped, the angle alphavaries continuously and randomly throughout the length of the filaments.

Since the twist of each filament is random along its length, a yarn madeup of a group of these non-round filaments is prevented from packing ina closely nested configuration. This is true even when considerabletension is applied to the yarn sufficient to straighten any randomcurvilinear crimp configuration. This latter property is particularlyuseful in increasing the bulk of tightly woven fabrics where loomtension and fabric construction tends to reduce the bulking effect dueto crimp. The random twist is likewise useful in highly crimped pileyarns or bulky knit structures where it tends to reduce objectionableglitter or luster associated with light reflection from the fibersurfaces.

In the preferred process of this invention, filaments and yarns meetingthe above objects are provided by a process in which a stream of acompressible fluid at a temperature above 275 F. and above thesecond-order transition temperature of the polymer of which the filamentis made, and preferably at least about 300 F., is vigorously jetted toform a turbulent plasticizing region. The yarn or filaments to betreated are positively fed at a rate greater than the yarn take-up Speedinto the fluid plasticizing stream so that the yarn is supported by itand individual filaments are separated from each other and whipped aboutin the hot turbulent plasticizing region, and is then cooled while beingmaintained at low tension. Under these conditions the yarn temperatureis above the cold poin as described more fully hereinafter and below themelting point of the yarn. During the jetting treatment, filamentshrinkage occurs because of the heat transmitted to the fibers. Theprocess elements such as temperature, pressure, fluid flow, yarn speed,tension and wind-up speed are adjusted so as to give a final yarn denier(measured in relaxed form after hot-wet relaxation) at least 12% greaterthan the feed yarn denier.

The treated yarn, of course, may be cut into staple after passingthrough the turbulent hot fluid. This process, therefore, provides ahighly productive way of treating tow which is to be used in stapleproducts. This process may also be used for setting dyes in the yarn.

A yarn padded with dyes may be either treated with a turbulent fluid toset the dyes in the fiber by diffusion through the fiber or it may betreated with 'a turbulent fluid to simultaneously bulk the yarn and setthe dyes.

The process of this invention can be used to improve the properties ofplasticizable fiber. The process is applicable primarily to continuoussynthetic filament yarns and multifilament yarns in particular although\monofilaments can also be treated in the same manner. Staple syntheticyarns can also be processed to give products of improved dyeability.

The products of this invention are different in fundamental physicalstructure from any of the treated yarns described in prior art. Duringthe jetting treatment, at least 12% lengthwise shrinkage of thefilaments and substantial deorientation of the filaments occur. Whenjetted under optimum conditions, this shrinkage and relaxation farexceeds that which occurs when the yarn is exposed to the same fluid atthe same temperature and under low tension for a long period of timewithout agitation. The instantaneous application of heat to fibers inthe jet and extremely short exposure time permit deorientation to occurbefore substantial crystallization can occur. The yarn does not,therefore, become permanently set before deorienting and does not becomebrittle or weak. This dynamic relaxation is responsible for aconsiderable amount of deorientation of the molecules and an increase incrystallinity. In addition, there is a large increase in dye receptivitywith little or no loss in tenacity. The improved combination ofdyeability rate and tenacity of filaments of this invention can beexpressed by the equation where D and D are the dyeability rates of thefilament before and after shrinking, respectively, and T and T are thetenacities of the filament before and after shrinking, respectively.This relationship holds true for both crimped and uncrimped filaments ofthis invention. Generally, all filaments of this invention have atenacity of at least 2 grams per denier.

The higher filament temperatures under relaxed conditions and therepeated stressing cause the amorphous molecular structure to open upgiving more lateral space between molecules and greater distance betweencrystallites along the fiber axis. The great changes in the amorphousmolecular structure are shown clearly by low angle X-ray patterns usingthe techniques described by W. O. Statton, I. Polymer Sci. 22, 385(1956). This new openedup condition, plus the deorientation whichoccurs, gives fibers with greatly improved dyeing rate withoutsubstantial reduction in tenacity. The dyeing rate can be increased 75%to 250% by the process of this invention and there is no change in thechemical composition of the fiber during treatment. Of course, moderateimprovements in dye rate have been shown in prior art by relaxed heattreatment, but such increases in dye rate with such small'losses intenacity and with luster advantages due to random filament twist havenot been known. In addition, the uniform turbulent heating in thepresent process permits much higher average filament temperatures to beobtained since there is no danger of surface filaments being heatedabove their melting point or fusing filaments.

All commercial procedures for manufacturing synthetic fibersinadvertently subject a portion of the yarn or certain segments of aportion of the yarn and filaments to plucks or other stresses as, forexample, when processing with fluids or passing over guides, whichcauses these yarns or segments to dye at a different rate and/ or to adifferent depth relative to the bulk of the yarn. Prior art processessometimes produce indentations along the filament length due to thepressing together of crossed filaments or result in bulging of thefilament walls due to a sharp creasing of the filaments. The dynamicrelaxation employed in this invention avoids these non-uniformities instructure and produces filaments with exceptional dyeability andtenacity but without cross-sectional configuration distortions. Theyarns produced by this invention thus are uniform in cross section, acharacteristic particularly noticeable with round filaments. The yarnsprepared by the process of this invention also have better dyeinguniformity than bulk yarns prepared by the twist-heat set method, bystutter-box crimping, or by other similar prior art crimping methodswhich produce filament distortion during the crimping process.

The process of this invention can be used to prepare such improvedproducts from any natural or synthetic plasticizable filamentarymaterial. Exemplary thermoplastic materials include polyamides, e.g.,poly(epsilon caproamide) and poly(hexamethylene adipamide) celluloseesters, e.g., cellulose acetate; polyesters, particularly polyesters ofterephthalic acid or isophthalic acid and a lower glycol, e.g.,poly(ethylene terephthalate), poly(hexahydro-p-xylylene terephthalate);polyalkylenes, e.g., polyethylene, linear polypropylene, etc.;polyvinyls and polyacrylics, e.g., polyacrylonitrile, as well ascopolymers of acrylonitrile and other copolymerizable monomers can betreated to give the improvement in properties discussed, andparticularly in dyeability. Copolymers of ethylene terephthalatecontaining less than 15% combined monomers other than ethyleneterephthalate and copolymerizable with ethylene terephthalate aresuitable. Spandex fiber properties are also improved. While thepreferred form of material is continuous filaments, the process andresultant improvements occur with staple yarns as well.

The process is useful for treating both monofilament and multifilamentyarns in textile deniers as well as the heavier carpet and industrialyarn sizes either singly or combined in the form of a heavy tow. Finecount and heavy count staple yarns can be processed both singles andplied. The process and product are also not restricted in the case ofthe synthetic materials to any one particular type of filament crosssection. Cruciform, Y-shaped, deltashaped, ribbon, and dumbbell andother such filamentary cross sections can be processed at least as wellas round filaments and usually contribute still more bulk than isobtained with round filaments.

The turbulent fluid used to treat the filamentary material may be air,steam, or any other compressible fluid or vapor capable of plasticizingaction on the yarn provided that it has a temperature above 275 F. andabove the second-order transition temperature of the filament. Hot airwill give suflicient plasticization in the turbulent region for manyfibers although it may be desirable for certain fibers to supplement thetemperature effect with an auxiliary plasticizing medium. Actually,steam is preferentially used in the subject process since it is a cheapand convenient source of a high pressure fluid with a compoundplasticizing action.

The temperature of the fluid medium must be regulated so that the yarntemperature does not reach the melting point of the fiber. However, withfibers made from fusible polymers, the most effective treatment andgreatest productivity is obtained when the temperature of the turbulentfluid is above the melting point of the fiber. In this case the yarnspeeds should be great enough so that melting does not occur. Because ofthegreat turbulence and the high heat, yarns are heated rapidly.Temperatures below 275 F. and lower than the second-order transitiontemperature (T of the yarn material should usually not be employedbecause under these conditions the dyeability of the filaments is notimproved and the utility of the fibers is reduced.

One of the essential elements of the process is that the filaments oryarn must be inherently elastic but must be rendered non-elastic andplastic in the turbulent atmosphere. The plastic condition may bebrought about by the temperature of the compressible fluid. In any case,the plastic condition of the filaments must be temporary and transitory.The term plasticizing or plastic is intended to mean that the conditionsto which the term relates are such that the filaments are in atemporarily flaccid, nonelastic, deformable condition. After theplasticizing conditions are removed such as by lowering the temperature,chilling, removing the solvent, or similar considerations, the filamentsand yarns must return to their normal elastic state. The use of an inertcompressible fluid such as air or steam under conditions which do notplasticize, soften, or render the filaments non-elastic, does not fallWithin the scope of the invention. Wet steam will fail to produce theimprovements in the yarn described above if the temperature of the yarndoes not reach a point sufliciently high to render it plastic andnon-elastic. On the other hand, relatively low temperatures may be usedif there is suflicient residual volatile solvent in the filaments. Itwill also be apparent that large amounts of non-volatile plasticizerssuch as dibutyl phthalate, tricresyl phosphate, oils, plasticizingresins, etc., are relatively permanent, and when these are present, theyarns will not return to an elastic condition and should be avoidedexcept for special purposes.

At high speeds and with certain polymers the fiber temperature should bewell above the second-order transition temperature. A preferred minimumtemperature defined as a cold point is given by J. W. Ballou and J. C.Smith in the Journal of Applied Physics, volume 20, page 499 (1949). Thecold point is the second inflection in the sonic modulus-temperaturecurve for the polymer or fiber in question. In general, this temperaturemay be 50 C. or more above the second-order transition temperatur Thetemperature of the filamentary structure is difficult to measure underthe usual working conditions. At high speed it is indicated that thesurface temperature of the fiber being treated may be well above thetemperature of the fiber interior. At low speeds, however, thefilamentary structure tends to come to equilibrium with the turbulentfluid temperature. The minimum temperature useful for treating thefilamentary structure at low speeds in the range of 1 to 5 y.p.m. may beconsidered the minimum useful yarn temperature for the process of thisinvention.

Yarn feed speed can be varied over a considerable range depending on thematerial, temperature, denier, degree of bulking, tension and othervariables. For economic reasons (productivity/position) the feed rateshould be at least 30 y.p.m. although slower speeds may be used forspecific items or special effect. Feed rates can run as high as 5000y.p.m. or even higher. Preferred feed rates are in the range of 300 to3500 y.p.m.

The temperature of the heating fluid must be high enough so that eitheralone Or in combination with some auxiliary plasticizing component, e.g.water, acetone or other solvent, it will soften or plasticize thefilamentary material passing through the heating area. The optimumtemperature, of course, varies depending upon the material beingtreated, the form of the material being treated; i.e., staple orcontinuous filament, the denier or yarn size, the rate of throughput,the degree of turbulence and/or pressure of the treating fluid, thedesign of the treating chamber, annd the extent of treatment desired.The temperature can range as high as 700 F. or more and a preferredrange is 400-600 F. The controlling factors are the characteristics ofthe material being treated and the temperature actually reached by thefilamentary material during treatment. The true upper limit, of course,is the temperature at which objectionable melting and/or chemicaldegradation of a given yarn takes place.

There are a number of means and apparatus whereby a turbulent stream offluid can be produced. Suitable jets or devices for treating afilamentary material with a turbulent plasticizing fluid to achieve theimprovements of this invention are described in US. Patents Nos.2,783,609 and 2,852,906 to Breen, and US. Patent No. 2,958,112 to Hall,as Well as those disclosed herein. After cooling, the yarn can "besubjected to normal processing tensions and wound into any of theconventional yarn packages. This cooling operation can be carried out bypiddling into a sliver can or onto a moving belt or screen but from aneconomic viewpoint, it is preferred to cool the yarn on-the-run as anintegral element of the overall crimping or bulking process. It ispreferred to use a positive cooling operation either immediately beforeor after the take-up roll-the important factor is that cooling iseffected prior to imposing any substantial tension on the hot plasticcrimped filamentary material.

Adequate cooling of the yarn can be achieved by passage across a chilledplate or roll. Passage of the yarn through a suitable liquid bath willalso cool the yarn adequately. The preferred embodiment, however, is theuse of a flow of a cooling fluid preferably a gas. This can be in theform of a jet that impinges the gas on the yarn bundle or it can takethe form of the jets described previously for treating the yarn with ahot turbulent plasticizing medium. Cooling jets can be designed toforward the yarn, apply a braking action, or so designed and balancedthat they exert neither a forwarding action nor a braking action.

The feed pressure of the hot plasticizing fluid will depend on thedegree of turbulence desired, feed speed, yarn denier, material beingprocessed, design of jet and the like. Pressures in the range of 20p.s.i.g. to 200 p.s.i.g. or more are useful while the preferred range isfrom 40-100 p.s.i.g. Normally economics will dictate that the optimumpressure is the lowest that still gives the desired treatment.

In US. Patent No. 2,783,609 it is disclosed that the filamentarymaterial should be removed abruptly from the fluid stream. It has beenfound advantageous in the subject process to remove the filamentsgradually from the hot fluid stream thus keeping the yarn hot for alonger period of time prior to quenching. The rapidly expanding fluidmedium will also give a cooling action outside of the yarn heating zone.

The process is well adapted for using a number of ends of yarn in thesame jet. Thus, it is possible to pass two to five or more ends througha single jet at the same time. The resulting yarn may have the ends wellblended or it may have treated ends which will be distinctly separateand independently windable depending on the proc essing conditions. Twoor more yarns may also be treated using different tensions or feed ratesso as to produce a tension-stable yarn with extensibility confined tothat of the shorter member. Likewise, two different types of yarn suchas nylon and rayon may be passed through the jet. The differentialshrinkage and heat-setting of the two types of yarn provide manyinteresting effects which are desirable for aesthetic reasons in textilematerials. It is also to be understood that any treatment of yarnsherein disclosed is to be construed as being applicable also to singlefilaments although for reasons of economy bundles of filaments or yarnsare treated. The term yarn refers to anylong or continuous length of abundle of filaments.

The synthetic filamentary materials to be treated by the process of thisinvention should preferably be in a high state of orientation to reducepilling in the finished fabrics. Drawable filaments tend to snag andpull out of the fabrics. The resulting fuzz fibers then tend to wind upinto fuzz balls usually referred to as pills in the finished fabric.When the oriented filamentary structures are passed under low tensionthrough the hot turbulent plasticizing fluid medium, a considerabledegree of deorientation and crystallization occurs.

Because of the unusually large increase in crystallinity, duringprocessing, the final yarns have a break elongation that is much smallerthan would be expected considering the large decrease in orientation.Similarly, the tenacity changes less than expected. At the same time,the yarns have a surprisingly high dyeing rate. The net result is toobtain unusual yarns having a desirable combination of low elongation,low pilling tendency, and rapid dyeability. Pilling is avoided becauseyarns of low elongation do not easily draw or pull out of the yarn orfabric when snagged to give long fuzz fibers. These undesirable fuzzfibers cause pilling by winding and entangling around one another untilballs of fuzz are formed. Of course, yarns with low elongations can beobtained in other bulk yarn processes by drawing the feed yarnadequately, but these highly drawn yarns then have relatively low dyeingrates.

The high degree of deorientation that accompanies the relaxation in apreferred process results in a gross increase in the filament denier ofthe yarn being treated. Some increase in denier, of course, accompaniesalmost any relaxation or bulking process, i.e., 110%. The filamentdenier of the new products formed by the subject process, however,increases in denier from 12 to 25% or more as compared to the filamentdenier prior to treatment. In this instance, of course, denier ismeasured by the change in filament weight per unit length with any crimpremoved by a light tension, eliminating the denier increase associatedwith crimp contraction.

Since it is likewise desirable that true fiber shrinkage accompanied bymolecular deorientation be accomplished, this shrinkage has beendetermined as follows:

Percent shrinkage= [1 Dem ]X D6D0 1 where Den is the denier of the yarnbefore treatment.

In order that the greatly improved dyeability may be achieved atacceptably low yarn elongation values, it isnecessary that the truefiber shrinkage accompanying this process be at least 12% and preferably25% or more.

Another parameter derived from the above measurements is useful incomparing yarns made at uncontrolled overfeed (FIGURE 1 without rolls41, 42, 45, and 46), with those made with the double roll or triple rollsystems (FIGURE 1 as shown). This has been termed the effective overfeed(EOF) and is calculated as follows:

All of the jets useful in the process of this invention arecharacterized by an arrangement for the common exit of the turbulentfluid and the yarn bundle being treated. The turbulent fiuid in allcases exhausts at high velocity relative to the yarn velocity. Onesurprising quality common to all jets which are adjustable is the needfor careful adjustment of the jet for optimum treatment. The jet shownin FIGURE 6 is easily adjusted by moving part 102 in or out with respectto part 95. A second adjustment is accomplished with the rotation ofpart 102 within the opening 104. In general, with heavy weight yarns,lip 105, on needle 103, should be withdrawn from the center position.For light denier yarns the optimum adjustment is with the lip beyond thecenter line of opening 100. The needle obstruction in the air flow alsoadds turbulence to the system which in some cases gives a superiorproduct.

Jets shown in FIGURES 2, 7, and 9 are also sensitive to adjustment. Ingeneral, the part (111, 124, or 143) introducing the yarn to the airstream should be slightly offcenter with respect to the orifice axis forbest action. A 60 angle 0: (FIGURE 6) favored ease of adjustment forbest action. In the jet of FIGURE 10 the eccentricity factor is providedby the abrupt change of direction of the high velocity fluid as itenters the yarn passage from one side. A variation of this apparatushaving several fluid entry ports spread about the periphery of the yarnpassageway is likewise made eccentric in its action on the yarn by usingports of different sizes and/ or by disposing them in a preferredunsymmetrical grouping. Stationary baifies within the jet may be usedsimilarly to provide the eccentric flow pattern.

The dyeing rates for feed and jet processed yarns are determined byanalyzing the dye baths or fibers. The amount of dye in the fiber isdetermined after dyeing for a short interval at a given temperature.Complete dye rate curves can be obtained by dyeing a number of separatesamples each for different lengths of time. For the purpose of thisinvention, however, the dye rate is defined as the amount of dyeabsorbed by the fiber in ten minutes at a given temperature. Each fibersample is dyed in a separate dye bath. The percent dye in the fiber maybe determined by ultraviolet spectral analysis of the dye bath or of asolution obtained by extracting dye from the fiber. The ratio by Weightof dye bath to yarn is 400: 1.

Slightly different methods are used for acid-dyeable polymers, basicdyeable polymers and those which dye with neither acidic nor basic dyes.Yarns having basic sites in the polymer such as the polyamide yarns, 6and 66 nylon, are dyed at 140 F. for ten minutes with 8% acetic acid and4% Du Pont Anthraquinone Blue SWF based on weight of fiber.Anthraquinone Blue SWF is Acid Blue 165 of the Colour Index, Society ofDyers and Colourists and American Association of Textile Chemists andColorists, 195 6. The percent dye in fiber is calculated from thepercent in the dye bath based on light transmission at Wave lengths of595 millimicrons. The initial dye bath with a known amount of dye servesas the standard sample for calculating concentration of dye in unknownsolutions after dyeing. The dye baths, including the standard, arediluted two-fold before measuring transmission. The concentrations ofdye in the bath are calculated from percent transmission by the use ofLamberts Law.

Yarns having acidic sites in the polymer such as modified polyethyleneterephthalates containing 2% or more of a sulfoisophthalic ester aredyed using 4% Du Pont Sevron Blue 5G and 4% Acetic Acid for minutes atthe boil in the absence of carriers. The percent dye in the fiber iscalculated from the percent dye in the bath using the transmission at660 millimicrons. The bath is diluted tenfold for this determination.

Yarns which do not have acidic or basic sites, such as unmodifiedpolyethylene terephthalate, are dyed with a dispersed color in theabsence of carriers. It is desirable to use a color which is sensitiveto physical changes in the fibers. The polymers with no acidic or basicgroups are dyed, therefore, with 4% Latyl Violet BN and 2% sodium laurylsulfate dispersing agent based on fiber weight for 10 minutes at theboil without carrier to establish the dye rate. After drying, fibersamples weighing 0.5 g. are analyzed for percent dye by extractingseveral times with chlorobenzene at 100 C. for about 5 minutes. Thecombined extracts are then diluted to a total volume of 100 ml. Analysisis made 'by using an ultraviolet spectrophotometer -at 580 millimicronwave lengths.

The steam treated yarns and the feed yarns are examined by standardX-ray diffraction techniques after relaxed boil-off. Methods fordetermining orientation angle are described by W. A. Sisson in theJournal of Textile Research, 7, 425 (1937) or Ingersoll, H. G., J. Appl.Phys. 17, 924 (1946). For the purposes of this invention, fibers aremounted for X-ray examination with 0.015 g.p.d. tension applied toremove substantially all crimp during exposure. The orientation angle isdefined here in terms of the azimuthal width of an intense equatorialdiffraction are. The angle is the width in degrees between the twopoints midway the peak intensity and the background intensity. Thisparameter decreases in value as orientation increases.

Higher temperature of the turbulent fluid tends to give higherorientation angles (low crystalline orientation). Orientation angles ashigh as 40 have been obtained by the process of this invention. It ispreferred that the treated yarn have an orientation angle greater thanthat of the feed yarn. Orientation angles for 6 nylon are obtained inthe range 13 to 35 degrees by varying the process condition. For 66nylon the orientation angle ranges from 13 to 40 degrees and forpolyethylene terephthalate homopolymer orientation angles are obtainedin the range 24 to 50 degrees. The basic-dyeable polyethyleneterephthalates obtained by copolymerization of terephthalate esters withsulfoisophthalic esters likewise deorient in this bulking process, andorientation angles of 22 to 50 degrees are obtained. Yarns fromcrystallizable polymers have greatly increased cryst'allinity aftertreating in the hot turbulent jet.

A surprising feature in the products of this invention is thecombination of high dyeability and tenacity and low orientation (highorientation angle). Otherknown processes (e.g., British Patents 684,046and 735,171) give high tenacity even though the filaments aredeoriented, but these other processes result in yarns with filamentsstuck together and with no crimp and without the improvement indye-ability of filaments of this invention.

If the overfeed is kept low enough at any given set of processingconditions, uncrimped yarns with random S and Z filament twist may thenbe obtained by the process of this invention. These uncrimped yarns aresuperior to other heat relaxed yarns since in addition to the noveltwist the filaments do not stick together and have very high dye rateand high tenacity.

Additional information may be obtained by studyiii g low angle X-raypatterns by the method of W. O. Statton (J. Polymer Sci. 22, 385 (1956),Crystallite Regularity and Void Content in Cellulosic Fibers as Shown bySmall Angle X-Ray Scattering). The low angle pattern shows a higheramount of crystallite placement regularity in the bulked yarns of thisinvention compared to the feed yarns. At the same time there is a greatincrease in the size of the long period. A typical steam bulked 66 nylonyarn, for example, had a long period of 98 A. while the feed yarn had along period of only 86 A. Higher temperatures and longer exposures tohot fluids in the jets give greater long periods. It is preferred thatthe treated yarn have a long period at least 4 A. greater than the feedyarn. By the process of this invention, filaments of various polymershaving long periods in the following ranges are obtained: 66 nylon,75-100 A.; polyethylene terephthalate, 95-140 A.; 6 nylon, 110 A.;copolymers of polyethylene terephthalate, l40 A.

According to this invention there are produced filaments havingoutstanding tenacity and very high dyeability, for example,poly(hexamethylene adipamide) having a long period of at least 90 A., atenacity (T of at least 3.0 and an orientation angle of at least(23.51.4T poly(epsilon caproamide), said filament having a long periodof at least 92 A., a tenacity (T of at least 2.5 and an orientationangle of at least (150.30T poly(ethylene terephthalate), said filamenthaving a long period of at least A., a tenacity (T of at least 1.0 andan orientation angle of at least (474.0T and copolymers of ethyleneterephthalate containing less than about 10% combined monomers otherthan ethylene terephthalate and copolymerizable with ethyleneterephthalate, said filament having a long period of at least 110 A., atenacity (T of at least 1.0 and an orientation angle of at least(28-2.3T

The following examples illustrate embodiments of the process of thisinvention and the products obtained. It is to be understood that whilethey illustrate the use of certain synthetic polymeric yarns havingcertain cross sections these may be substituted by any other polymericyarn or filament herein disclosed having any cross section such ascircular, square, rectangular, flat, star-shaped, or those having threeor more cusps and similar shapes. Likewise the denier, speed,temperature, take-up speed, and other considerations may vary widelywithin the limits given above.

All of the filaments produced by the process embodiments illustnated inthe following examples have completely random S and Z twist as describedheretofore.

EXAMPLE I th an acid dye (Du Pont Anthraquinone Blue SWF) increased from0.42% in minutes for the feed yarn to 1.43% for the 450 F. bulked yarn.The orientation angles increase using steam at three difie d from 13.0degrees to 20.8 degrees as the temperature increased to 450 F.

zero-twist semi-dull yarn with round filament cross section. Each of theyarns was processed using 500 yardsper-minute feed speed and 55 p.s.i.steam. Very moderate crimp was obtained at 300 F., but at the highertemperatures, such as 610 F. and 660 F., excellent crimp was obtained,and the dye rates were very greatly increased. The bulked yarns weredyed with Latyl Violet BN, a dispersed dye, in the absence of carrier.Autoclaved samples, on the other hand, had greatly reduced dye rateafter treatment at 275 F., 325 F., or 350 F. The orientation anglesincreased for the autoclaved yarns and for jet treated yarns, but onlythe jet treated yarns had the combination of good crimp, high dye rate,and high tenacity. The jet of FIGURE 1 is described in detail in HallU.S.

Other samples of the same feed yarn were treated by lrn- Patent No.2,958,112.

TABLE II Dye rate Filament tensile properties (boiled off) dispersedOrientation Yarn treatment dye (percent Denier per angle absorbed inTen, Elong, Mi, filament (deg.) 2

10 min. at g.p.d. percent g.p.d., (d.p.t.)

boil) Feed yarn 1.02 4. 7 48 59 2. 2 25 Jet, 300 F., 19% overfeed 0. 334. 8 44 60 2. 2 Jet, 400 F., 27% overieed 0.57 4. 6 54 50 2. 3 Jet, 500F., 42% overfeed 1. 06 4. 2 75 33 2. 5 24. 1 Jet, 610 I 2, 80%over-feed... 1. 41 3.1 127 16 3. 2 Jet, 660 F., 125% overfeed 2. 32 2. 8126 21 3. 2 43. 6 Autoclave, 275 F., minutes, H20. 0 25 4. 8 60 55 2. 2Autoclave, 325 F., 15 minutes, H20. 0. 26 4. 5 53 54 2. 3 Autoclave, 350F., 15 minutes, 1110. 0. 08 4. 1 45 57 2. 4 18. 4

1 Mi is initial modulus which is the slop val (load in grams/denier v 1Measured using 100 diffraction spot 15 minutes at 275 F. or 325 F. in asealed autoclave. There was a drastic reduction in tenacity to 1.4 gramsper denier in the autoclaved sample prepared at 325 F. The dye rate forthe autoclaved yarn increased to 1.20% for the sample treated at 325 F.The autoclaved yarns had no crimp even though the orientation angleincreased greatly. The data show that the yarns of this invention havethe rate combination of high tenacity and high dye rate. At the sametime, these yarns may be produced with curvilinear crimp. The amount ofcrimp and the dye rate each increased as the jet temperature increased.The data from this experiment are shown graphically in FIGURE 12 whereline A represents autoclaved yarn and line B refers to bulked yarnprepared 45 in a steam jet.

mersing in water for e of the straight line portion of stress-straincurves beyond the point 01 s. fractional elongation).

EXAMPLE III A modified polyethylene terephthalate yarn having 2.0%sulfoisophthalic ester in the polymer was treated as shown in Table V.The feed yarn was a single end of 70-denier, SO-filament, zero-twist,semi-dull yarn having filaments with triangular cross section. All ofthe yarns were processed in the jet at 500 y.p.m. and p.s.i. steampressure. Moderately crimped filaments were obtained at the lowertemperatures. Very highly crimped filaments were obtained from the jettreatment at 500 F. The treated yarns were dyed with basic dyes and thedye rate increased very greatly for the 500 F. samples. This increase indye rate was obtained without appreciable loss TABLE I Dye rate Filamenttensile properties (boiled ofi) acid dye Orien- Yarn treatment (percentDenier tation absorbed Ten., Elong, Mi, per angle in 10 min. g.p.d.percent g.p.d. filament (deg) I at 140 F.) (d.p.f Feed yarn 0. 42 6.0 3629 15. 8 13. 0 Jet, 275 F., 40% 0v 0.55 6. 5 38 25 15. 7 13. 3 Jet, 325F., 40% 0v 0. 71 7.1 45 24 15.3 14. 4 Jet, 450 F., 100% overteed 1. 435.0 98 8. 5 19. 7 20. 8 Autoclave, 275 F., 15 minutes, H20. 0 83 5. 7108 26 14. 8 14.4 Autoclave, 325 F., 15 minutes, H20. 1 20 l. 4 23 2118. 7 18. 6

1 Measured using 100 difiraction spot.

EXAMPLE I1 A single end of continuous filament yarn spun frompolyethylene terephthalate was bulked using the jet of FIGURE 1. Thefeed yarn was a -denier, 34-filament,

in tenacity. On the other hand, yarns which were treated in theautoclave, as shown in the table, had much lower dye rates and were notcrimped.

TABLE III Dye rate Filament tensile properties (boiled ofi) Orienbasicdye tation Long. Yarn treatment (percent ab- 'Ien., Elong, Mi. Denierper angle period (A.)

sorbed in 10 g.p.d. percent g.p.d. filament (deg) min. at boil) (d.p.f.)Feed yarn 1. 26 3. 2 61 44 1. 5 18. 5 9 Jet, 300 F., 19% overfeedun 0.903. 3 52 48 1. 6 22. 7 98 Jet, 400 F., 35% overieed 1. 24 2. 8 59 43 1. 6Jet, 500 F., 145% overieed l 2. 50 2. 6 91 25 2.0 24. 7 122 Autoclave,275 F., 15 minutes, H 0. 16 2. 6 25 50 1. 4 Autoclave, 325 F., 15minutes, H10. 0. 66 2. 0 16 59 1. 4 15. 1 102 1 Mi is initial modulus(load in grams/denier vs. fractional elongation).

2 Measured using difiraction spot.

which is the slope of the straight line portion of stress-strain curvesbeyond the point of crim p removal EXAMPLE IV Two ends of a continuousfilament polyhexamethylene adipamide yarn were processed in the jet 'ofFIGURE 1,

using three different overfeeds as shown in Table IV. The yarn was780-denier, 51-filament, 0.75 Z twist bright nylon with round filamentcross section. Each of the yarns was processed at 108 yards-per-minutefeed speed and 85 p.s.i. steam pressure. In each case, the steamtemperature was 450 F. The dye rates, tensile properties, andorientation angles for the processed yarns are shown in Table IV. Theyarn which was processed with 22% over feed was an uncrimped straightyarn and had very greatly increased dye rate over the feed yarn. Theyarn processed at 40% overfeed had curvilinear crimp in the filamentsand had still higher dye rate. The yarn processed with 100% overfeed wasa highly bulked yarn with excellent crimp, high dye rate, and goodtensile properties.

16 tained having a dye rate with Du Pont Anthraquinone Blue SWF, an aciddye, of 2.0% dye in 10 minutes. The filaments were not crimped. It had atenacity of 3.9 g.p.d. The orientation angle was 17 degrees.

Since many difierent embodiments of the invention may be made withoutdeparting from the spirit and scope thereof, it is to be understood thatthe invention is not limited by the specific illustrations except to theextent defined in the following claims.

We claim:

1. A process for treating a synthetic organic filamentary strand toprovide improved dyeability at high tenacity without impartingcurvilinear filament crimp which comprises feeding the strand at a rateof at least yards per minute to a plasticizing stream of compressiblefluid having a temperature of at least 275 F. and sufficient velocity tomomentarily separate the filaments, treating TABLE IV Dye rate Filamenttensile properties (boiled ofi) acid dye Or en- Overfeed, Type of crimp(percent Denier tation percent absorbed in Ten., Elong., Mi, per angle10 min. at g p.d. percent g.p.d. filament (deg) 140 F.) (d.p.f.)

Feed yarn 0. 42 6.0 36 29 15.8 13. 0 22 1. 08 5. 4 55 20 16. 4 19. 0 40g 1. 46 4. 9 80 11 19.1 21. 0 100 Highly crimped--- 1. 43 5. 0 98 8. 519. 7 20.8

EXAMPLE V the separated filaments in the stream to shrink the fila-Filament yarn (70-denier, -filament, zero-twist, Y cross section) ofpoly(ethylene terephthalate) modified with 2.0% of a sulfonatedderivative of isophthalic acid to provide dyeability with basic(cationic) dyes, was fed to a steam jet at 393 y.p.m. with an overfeedof 40% through a jet similar to FIGURE 1 of US. Patent No. 3,005,251issued Oct. 24, 1961, to Hallden and Murenbeeld. The steam supply to thejet was superheated to a temperature of 460 F. at a pressure of 71p.s.i. The yarn was wound up at a speed of 280 y.p.m. The treated yarnpicked up more than twice as much basic dye as the untreated yarn whendyed with Du Pont Sevron Blue 56. The treated yarn, in fact, had 105%improvement in dye rate over the untreated yarn. There was no crimp inthe jet processed yarn, but the individual filaments possessed random Sand Z twist throughout their length. This improvement in dye rateachieved with the treated yarn is not specific to the conditions used inthis given dyeing procedure. Numerous other basic dyes had equivalentimprovement including Du Pont Brilliant Green Crystals, Du PontFuchsine, and Sevron Blue BGL. Similar improvements in dyeability havebeen achieved with fabrics prepared from the yarns using bath to fabricratios as low as 15:1 and as high as 500:1.

EXAMPLE VI A single end of poly(epsilon-caproamide) yarn was bulked inthe jet of FIGURE 1. The yarn was 4200-denier, 224-filament, zero-twistbright yarn with round filament cross section. The yarn was passedthrough the jet with feed speed of 200 yards per minute, steamtemperature 530 F., and 44% overfeed. An unbulked yarn was obments atleast 12% and increase the rate of dyeability at least withdrawing thestrand from the stream at a lower rate than said feed rate whichprovides at most 40% overfeed to the stream, the overfeed being adjustedto provide for said shrinkage without curvilinear crimping of thefilaments, and collecting the treated strand.

2. A process as defined in claim 1 wherein said overfeed is from 12% to30%.

3. A process as defined in claim 1 wherein said compressible fluid issteam at 400 to 600 F.

4. A process as defined in claim 1 wherein the strand is withdrawn fromthe fluid stream within a sufiiciently short time to provide a filamenttenacity in excess of 0.8 T (D /D where T is the filament tenacitybefore treatment, and D and D are the dyeability rates of the filamentbefore and after treatment.

References Cited UNITED STATES PATENTS 2,379,824 7/1945 Mummery 28-722,435,891 2/1948 Lodge 57-34 3,380,242 4/1968 Richmond et a1. 28-1FOREIGN PATENTS 161,076 2/1955 Australia.

MERVIN STEIN, Primary Examiner.

Us. 01. X.R. s7 140, 157

